import itertools

list1 = [1, 2, 3]
list2 = ['a', 'b']
list3 = ['x', 'y', 'z']

# 拼接并填充
result = itertools.zip_longest(list1, list2, list3, fillvalue='NA')

for item in result:
    print(item)

result2=zip(list1,list2,list3)
for item in result2:
	print(item)